With the use of any form of electrical appliance, there is a need to electrically insulate conductors. With the push to continuously reduce the size and to streamline all electrical and electronic systems there is a corresponding need to find better and more compact insulators and insulation systems.
Good electrical insulators, by their very nature, also tend to be good thermal insulators, which is undesirable. Thermal insulating behavior, particularly for air-cooled electrical equipment and components, reduces the efficiency and durability of the components as well as the equipment as a whole. It is desirable to produce electrical insulation systems having maximum electrical insulation and minimal thermal insulation characteristics.
Though many factors affect the art of electrical insulation, the field would benefit even more from the ability to transfer heat, without reducing other desired physical characteristics of the insulators. What is needed is improved electrical insulation materials that have thermal conductivity higher than that of conventional materials, but that do not compromise the electrical insulation and other performance factors including structural integrity.
Electrical insulation often appears in the form of tapes, which themselves have various layers. Common to these types of tapes is a fabric layer that is bonded at an interface to a paper layer, both layers tending to be impregnated with a resin. The paper layer will be composed of materials that are highly electrically insulating, such as mica. Improvements in the manufacture of enhanced dielectric strength insulation tapes are taught in U.S. Pat. No. 6,190,775. If the thermal conductivity of the fabric, independent from or in conjunction with its use in a tape, can be improved then the electrical system will see marked improvement.
Additional use of fabrics is in the pre-printed circuit board industry. The circuit board backings are fabrics in sheet form impregnated with resins then laminated. Since electronics are adversely affected by heat, even slight improvements in the thermal conductivity of circuit board backings will increase efficiency. Other problems with the prior art also exist, some of which will be apparent upon further reading.